Broadcast License, Goodwill and Other Intangible Assets (Schedule of certain key estimates and assumptions used in impairment test) (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Measurement Input, Discount Rate [Member] | Minimum [Member]
Impairment measurement input	12.6	12.2	12.0
Measurement Input, Discount Rate [Member] | Maximum [Member]
Impairment measurement input	13.0	12.2	12.0
Measurement Input Operating Profit Margin [Member]
Impairment measurement input	36.4
Measurement Input Operating Profit Margin [Member] | Minimum [Member]
Impairment measurement input	17.8	19.0	19.0
Measurement Input Operating Profit Margin [Member] | Maximum [Member]
Impairment measurement input		36.4	36.4
Measurement Input, Long-term Revenue Growth Rate [Member] | Minimum [Member]
Impairment measurement input	0.2	0.0	0.5
Measurement Input, Long-term Revenue Growth Rate [Member] | Maximum [Member]
Impairment measurement input	2.9	2.9	2.9